This invention relates to bed frames and, more particularly, to bed frames which have an adjustable width and which are foldable to a compact position.
Bed frames for supporting a box spring and mattress above a floor typically include a pair of spaced, parallel, horizontally disposed side rails, and a pair of spaced, parallel, horizontally disposed end rails which extend substantially transversely between the side rails for holding the side rails in spaced, parallel relationship. The end rails typically comprise a pair of elements which are locked together.
A problem has long existed in the art because conventional frame members of the above type have not provided positive interlocking engagement between the end rail elements and have required the use of a large number of fasteners. As a result, the assembly and disassembly of the end rail elements is time consuming and complicated and if, by chance, the width has been assembled too narrow or too wide for the particular box spring and mattress, the box spring and mattress should be completely removed before any readjustment of the width can be made.
Commonly assigned U.S. Pat. No. 4,078,270 to Nowell attempts to overcome this problem by providing means for fastening together the elements of a transverse member of a bed frame while still allowing for adjustments in the width of the bed frame. However, one of the disclosed embodiments is a relatively complicated structure which includes a sleeve that circumscribes and protrudes outwardly from both transverse elements. In the other disclosed embodiment, the fastening means provides for adjustments in the transverse width, but does not fasten the two transverse elements together; the two elements are in the shape of C-shaped channels which are received with one another to restrain the elements in all directions except axially.
Commonly assigned U.S. Pat. No. 3,757,361 to Harris et al. discloses an adjustable transverse member that has rivets on one transverse element that are receivable in keyhole slots in the other transverse element. However, the width of the transverse member can be adjusted only to the predetermined spacing of the rivets and keyhole slots. Accordingly, variations in width can be made to accommodate queen-size or king-size bedding, but slight adjustments in width to compensate for minor variations in width of an inch or so for a particular size of bedding, such as queen-size, cannot be readily made.
Another problem with prior art bed frames is to minimize the amount of space required for shipping the bed frames while maximizing the ease of assembling the bed frames. One attempt at solving this problem is disclosed in U.S. Pat. No. 3,123,837 to Paine et al. which teaches a bed frame that has end rail elements that are folded to a position parallel to the side rails. However, in the folded position, a relatively wide space is inherently produced between the end rail elements and the respective side rails. As a result, relatively large shipping containers are required for the bed frames.
The aforementioned patent to Nowell also discloses transverse elements which are rotatable relative to the side members, but is limited to a structure where the transverse elements are nested within the side members when folded.